<style>
  .login {
    background: #eceeee;
    border: 1px solid #42464b;
    border-radius: 2px;
    height: 70px;
    margin: auto;
    width: 120px;
    top: 100px;
    left: 100px;
    right: 0px;
    bottom: 0px;
    text-align: center;
    position: absolute;
  }

  .login h1 {
    background-image: linear-gradient(top, #f1f3f3, #d4dae0);
    border-bottom: 1px solid #a6abaf;
    border-radius: 2px 2px 0 0;
    box-sizing: border-box;
    color: #727678;
    display: block;
    height: 15px;
    font: 600 5px/1 'Open Sans', sans-serif;
    padding-top: 5px;
    margin: 0;
    text-align: center;
    text-shadow: 0 -1px 0 rgba(0, 0, 0, 0.2), 0 1px 0 #fff;
  }

  input[type="password"],
  input[type="text"] {
    background: linear-gradient(top, #d6d7d7, #dee0e0);
    border: 1px solid #a1a3a3;
    border-radius: 1px;
    box-shadow: 0 1px #fff;
    box-sizing: border-box;
    color: #696969;
    height: 13px;
    margin: 10px 0 0 10px;
    padding-left: 3px;
    transition: box-shadow 0.3s;
    width: 100px;
    font-size: 5px;
  }

  input[type="submit"] {
    width: 100px;
    height: 12px;
    display: block;
    font-family: Arial, "Helvetica", sans-serif;
    font-size: 5px;
    font-weight: bold;
    color: #fff;
    text-decoration: none;
    text-transform: uppercase;
    text-align: center;
    text-shadow: 1px 1px 0px #37a69b;
    padding-top: 2px;
    margin: 6px 6px 0 10px;
    position: relative;
    cursor: pointer;
    border: none;
    background-color: #37a69b;
    background-image: linear-gradient(top, #3db0a6, #3111);
    border-top-left-radius: 1px;
    border-top-right-radius: 1px;
    border-bottom-right-radius: 1px;
    border-bottom-left-radius: 1px;
    box-shadow: inset 0px 1px 0px #2ab7ec, 0px 1px 0px 0px #497a78, 0px 10px 5px #999;
  }

  .shadow {
    background: #000;
    border-radius: 4px 4px 1px 1px;
    box-shadow: 0 0 20px 10px #000;
    height: 2px;
    margin: 6px auto;
    opacity: 0.2;
    width: 90px;
  }

  input[type="submit"]:active {
    top: 2px;
    box-shadow: inset 0px 1px 0px #2ab7ec, 0px 1px 0px 0px #31524d, 0px 1px 3px #999;
  }
</style>

<div class="login">
  <input type="text" placeholder="话题：如天气、生活" id="topic" name="topic" value="">
  <input type="submit" value="OK" name="okButton">
  <input type="submit" value="Cancel" name="cancelButton">
</div>
<div class="shadow"></div>